Maxillary bone extensor

ABSTRACT

A maxilla extension apparatus that extends the maxilla in lower forward direction, wherein a band is installed on the maxilla dentition, fixed onto a slide rail, and an arm is fixed onto the zygomatic bone. With this embodiment, a maxilla extension apparatus can be offered, an apparatus of which can accurately and less invasively extend the maxilla in a short time.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to an apparatus utilized to conduct maxilla extension surgery in cases of maxilla regressive growth and mandible excessive growth.

[0003] 2. Description of the Prior Art

[0004] Disorders such as maxilla regressive growth and mandible excessive growth represented by harelip and cleft palate symptoms, occur with abnormal occlusion in which the upper and lower jaw bones do not bite, and cause declined tongue disposition and muscle function abnormalities. A conventional treatment conducted on maxilla regressive growth patients is to fix elastic rubber on the canine tooth of the maxilla dentition part, give some pulling force forward to open the maxilla peripheral sutura, and promote bone repair. Another conventional method is to incise the maxilla, and move the maxilla forward surgically.

[0005] 3. Summary of this Invention

[0006] The treatment period for fixing elastic rubber on the maxilla dentition canine tooth and pulling the jaw forward would take about 1 to 2 years, but this method can extend the bone for only 1 to 2 mm, a treatment of which is not adaptable for patients with notable harelip or cleft palate cases. Also, as the treatment takes a long time, it is difficult to maintain cooperation from the patients for such an extended period of time. The surgical method to incise the maxilla and move the maxilla forward, is highly invasive, and would generate issues such as necrosis of the dental pulp in connection with the bone incision, and disorder of nasopharynx occlusive functions.

[0007] The nasal maxilla complex has the skeletal structure with many suturae, and the sutura parts open during the growth period, to let grow and extend the bone tissue. Therefore, it is possible to promote and accelerate the bone growth by placing some mechanical burden on this part.

[0008] This invention enables the acceleration of bone growth in a short time such as one week, by directly fixing the zygomatic bone and the maxilla dentition, placing mechanical burden by supplying rotation force with a rotation shaft from the inside of the mouth. As the shaft can be removed and is detachable, the fact that a maxilla extension apparatus is mounted inside is not so obvious from the outside. Once the bone is extended, the maxilla extension apparatus is removed after a certain fixation period, and the removal can be done easily by unfastening the screw on the zygomatic bone side, and by unfastening the band on the maxilla dentition, a method of which is highly non-invasive compared to conventional bone incision method.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is an explanatory drawing depicting an embodiment of the maxilla extension apparatus.

[0010]FIG. 2 is a perspective drawing of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereafter, a description of the preferred embodiments of this invention is made in reference to drawings. FIG. 1 is a drawing of an embodiment of this invention. FIG. 1 shows a maxilla extension apparatus installed onto the left part of a face. The maxilla is approached from the inside of the mouth, after which the oral membrane is incised, the position of the Zygomatic bone maxilla sutura 14 is confirmed, then the tip of Zygomatic bone fixing arm 2 is fixed onto Zygomatic bone 10 at the end of the seam. FIG. 1 shows that a Flexible metal 13 is spread like a maple leaf, and the tip ends of the metal are fixed onto the root part with Screw 12. The material of the flexible metal should be pure titanium or stainless steel SUS316L and such, materials with high compatibility with body parts. Zygomatic bone fixing arm 2 is connected with Flexible metal 12 with welding, to assure sufficient hardness. The Forward extension shaft 7 and Angle adjustment rotation shaft 6 both of which are extruded, are used to adjust the extension length and the angle with Driver 8. The target growth for the bone extension is 1 mm per day, for reference. Usually, 3 to 4 mm of growth is sufficient in many cases, but there are cases in which the growth should be approximately 1 cm. The length of the growth extension can be controlled easily with the screw pitch set at 1 mm per rotation. Idealistically, the bone growth can effectively be accelerated when the apparatus is tilted at an angle of 38 degrees to the lower side, measured from the bite plane. The slash marked part in the drawing shows the left nasal maxilla complex to be extended to the lower forward direction. In actual application, same apparatus is mounted on the right side, conducting extension on both sides simultaneously.

[0012] Fig.2 is a perspective drawing of the main part of this invention. Different from Fig.1, this drawing shows the right side of a face. The head part of Angle adjustment rotation shaft 6 and Forward extension shaft 7 are formed hexagonally, which can be connected to the tip of the driver. Angle adjustment rotation shaft 6 is cylindrical when inside the main part, with screw-thread cutter in the perimeter of the cylinder, forming Screw 4. In conjunction with this screw, the inside of Angle adjustment movable cylinder 15 also has screw-thread cutter features inside. Angle adjustment shaft 3 that grasps onto the outside of the Angle movable cylinder 15 is connected, and the shaft is further connected to the center part of Zygomatic bone fixing arm 2. When Angle adjustment rotation shaft 6 is rotated, Main part 1 tilts upward or downward. Forward extension shaft 7 has the same structure, wherein the inside of the main part becomes Forward extension screw 5. Movable cylinder 16 for extension that screws onto Screw 5 is connected to Slide rail 9 via a window on Main part 1, and therefore the Slide rail 9 moves forward or backward when Forward extension shaft 7 is rotated. Metal band 11 which is made from the mold of each patient is welded onto this Slide rail 9, and the product is completed.

[0013] As in the above description, this invention enables maxilla extension in a short time, with very low invasiveness, without causing pain on the part of the patient. The surgeon can conduct treatment from the inside the mouth, obtaining good effects with simple surgery. The extension length and the angle can be managed and controlled easily, and a highly accurate adjustment is possible. Furthermore, each apparatus is used as an exclusive apparatus for each patient, and this enables the fixing force of each apparatus to be stronger, causing less uncomfortable feeling on the part of the patient. 

What is claimed is:
 1. A maxilla extension apparatus to be utilized in cases of maxilla regressive growth and mandible excessive growth, to promote the bone growth by pulling the nasal maxilla complex forward and extending the maxilla peripheral sutura, an apparatus with the structure to fix a slide rail on the maxilla dentition on both the right and the left sides of the face, with the upper part of an arm fixing the zygomatic bone onto both the right and the left zygomatic bones, and rotate a forward extension rotation shaft which extrudes in the front direction of the main part, then a connecting forward extension screw pushes out the slide rail in the forward direction, and thence extend the maxilla bone.
 2. A maxilla extension apparatus as claimed in claim 1, with the characteristic of the screw pitch set to enable the movement of the slide rail to move 1 mm forward when forward extension rotation shaft is rotated once.
 3. A maxilla extension apparatus as claimed in claim 1 and 2, with the structure of the angle adjustment rotation shaft is extruded in forward direction from the main part, and by rotating the shaft the angle adjustment screw inside the main part rotates, the rotation of which is received by the lower part of an angle adjustment shaft moving forward and backward inside the main part, then the upper part of the angle adjustment shaft is fixed with a screw onto the center part of zygomatic bone fixing arm, then the lower part of the zygomatic fixing arm is fixed with a screw onto the main part, and when the angle adjustment rotation shaft is rotated, the main part tilts upward or downward, to freely adjust the angle of the bone extension.
 4. A maxilla extension apparatus as claimed in claim 3, having a feature of a screw pitch which is set to change the angle one degree when the angle adjustment rotation shaft is rotated once.
 5. A maxilla extension apparatus as claimed in claim 1, 2, 3 and 4 with the feature of the driver to rotate both the forward extension shaft and the angle adjustment shaft, the driver being a detachable system that can be removed from the front side of the main part.
 6. A maxilla extension apparatus as claimed in claim 1, 2, 3, 4 and 5, with the structure of the upper part of the zygomatic bone fixing arm to fix the apparatus to the zygomatic bone, the upper part of the arm made of flexible metal, with a multiple number of holes to let pass screws to fit the apparatus to the zygomatic bone and to fix the apparatus onto the screw.
 7. A maxilla extension apparatus as claimed in claim 1, 2, 3, 4, 5, and 6, with the feature of the metal belt type band that is fixed on the peripheral of a multiple teeth, to be either welded or waxed onto the inner side of the slide rail.
 8. The manufacturing method of the maxilla extension apparatus as claimed in claim 7, wherein the mold of the upper jaw dentition of each patient is taken in advance before surgery, a metal belt type band is wound around the teeth of which the mold was taken, the slide rail is fixed after welding or waxing on the outer side of the band, and thus making it possible for the manufacturing of each maxilla extension apparatus exclusive for each patient. 